Define :BEFORE methods that check for finalized on some class readers.
Add many more comments.
Define new accessor PRECEDENCE-LIST, and remove writer C-PRECEDENCE-LIST.

During class finalization, we need to store the precedence list
computed with COMPUTE-CLASS-PRECEDENCE-LIST.  The AMOP says that step
1 of finalization does that and then associates the result with the
class.  The AMOP also hints that steps 2 and 3 of finalization might
use CLASS-PRECEDENCE-LIST to access the result of step 1.  However,
this is not possible, because the AMOP also says that
CLASS-PRECEDENCE-LIST signals an error if the class is not finalized,
and during finalization, this is not yet the case.  Our solution is to
introduce an accessor (whose name is not exported) called
PRECEDENCE-LIST so that we have both an alternative reader for the
slot and a writer to store the result of calling
COMPUTE-CLASS-PRECEDENCE-LIST.
More comments and make it possible to assume superclasses finalized.
More comments.
Phase 4 component for installing some (but not all) bridge generic functions.
Phase 4 component for finalizing inheritance of target classes.
Added accessor INSTANCE-SIZE to avoid recomputing size instances during allocation.
Removed code that is no longer used.
Minor improvements.
Updates according to recent design decisions.
More about bootstrapping phases.
More about the advantages of our representation of heap instances.
Use new accessor INSTANCE-SIZE.
Removed unused slot and associated accessor.
Removed unused file.
Removed reader GF-METHODS, because it is no longer needed.
Introduced alternative reader INITARGS like SLOT-DEFINITION-INITARGS.

Unfortunately, the accessors for direct and effective slot definitions
are the same.  This is unfortunate because of problems during
bootstrapping.  Direct slot definitions are accessed during class
finalization in order to create effective slot definitions and
effective slot definitions are needed for initializing instances, so
they are needed at the same time.  In Phase 4 of bootstrapping, the
direct slot definitions that are used in class finalization are target
instances, but the effective slot definitions needed for initializing
instances are bridge instances.

The solution (which is not pretty) is to define a set of alternative
readers for slot-definition objects and make sure that during phase 4,
the alternative readers are used in class finalization.
Introduced alternative reader INITFUNCTION like SLOT-DEFINITION-INITFUNCTION.
Introduced alternative reader INITFUNCTION like SLOT-DEFINITION-INITFUNCTION.